the Science of the l&al Emhnment M-laurulcw~~- i”m!bE.~~IUR-“lIbMM ELSEVIER The Scienceof the Total Environment 171(1995) 243-264 Regulation of toxic chemicals in the Mediterranean: the need for an adequate strategy R.J. Swindlehurst”, P.A. Johnston*b, S. Triindle”, R.L. Stringer”, A.D. Stephensona, I.M. Stoneb aGreenpeace Exeter Research Laboratory bEarth Resources Centre, University of Exeter, Exeter, EX4 4QE, UK Received 17November 1993; revision received 2 June 1994;accepted 17January 1995 Abstract Recognising the need to regulate the impact of pollutants on the Mediterranean region, the Mediterranean States have formulated the Barcelona Convention and the protocols related to it. This incorporates commitments to reduce inputs of chemicals which have been retrospectively identified as harmful. In particular, the Convention has identified the organohalogens as a priority group. Any commitment, however, to reductions of chemical inputs assumes a comprehensive framework within which both these and the effects of control measures can be reliably quantified. There are a number of shortcomings which can be identified in existing systems in the Mediterranean region. Effluents, even with respect to the organohalogen group, are extremely complex in character. In the region as a whole, monitoring efforts are limited. Existing programmes do not allow input or input reduction data to be computed with adequate statistical power, or chemical phase-outs to be verified. This paper highlights some of the practical problems encountered with reference to organohalogen compounds and the advantages of regulating these compounds as a group. Analytical results from two case studies in the Mediterranean are presented to illustrate this and the results are discussed in relation to alternative strategies. Keywords: Mediterranean; Venice Lagoon; Ebro River; Organohalogens; Regulation 1. Introduction As noted by Fowler (1986), several of the oceanographic and geographic characteristics of the Mediterranean Sea render it vulnerable to inputs of anthropogenic pollutants. The Sea is relatively shallow and semi-enclosed with only * Corresponding author. limited natural water exchange at the Straits of Gibraltar and the Black Sea and with very minor exchange through the Suez Canal. Thus, the ma- jor water loss from the sea is by evaporation and persistent pollutants tend to accumulate rather than be removed by flushing. A general lack of tides, coupled with weak coastal currents act to reduce the dispersion of pollutants. The construc- tion of dams on major rivers reduces seasonal extreme freshwater flows. Finally, the high species 0048-9697/95/$09.50 0 1995 Elsevier ScienceBV. All rights reserved. SSDZ 0048-9697(95)04719-H